Nevada CDL: Tanker Vehicles Practice Test

Not quite. The answer is closed before you drive the vehicle.

To help prevent leaks, close all manhole covers before you drive the vehicle.

Not quite. The answer is Always

Escape ramps are designed with soft gravel, upgrades, or both, to slow down vehicles that experience brake failure on a downgrade. Regardless of the type of CMV you're driving, if your brakes have failed, head for one of these escape ramps, which can save lives, equipment, and cargo.

Not quite. The answer is the movement of the liquid.

It takes special skills to drive a tanker carrying liquid cargo because of the vehicle's high center of gravity and the possibility that the liquid cargo may surge forward and backward or from side to side. The liquid surge can push the vehicle dangerously forward or sideways, which can cause a rollover. Once a side-to-side surge begins, unless the driver takes action, the tank will keep swaying more and more until the vehicle rolls over.

Not quite. The answer is Wet roads can double the stopping distance at any speed.

To control surge, know the stopping distance of your vehicle and brake far in advance of a stop whenever possible. Bear in mind that your vehicle's stopping distance on wet roads will be about double its stopping distance on dry roads.

Not quite. The answer is Slow to a safe speed before entering, then accelerate slightly through the curve.

The posted speed for a curve may be safe for cars but not for tankers because of their relatively high center of gravity. Tests have shown that a tanker can roll over on a curve when traveling at the posted speed. The safest way to take a curve in a tanker is to slow down before the curve and then accelerate slightly through the curve. Braking in a curve risks a skid.

Not quite. The answer is There will be less front-to-back surge than there is in a tanker without baffles.

Baffled tanks have bulkheads with holes to reduce forward-and-backward surge. This will reduce the chance that forward surge will push your vehicle dangerously forward when you're slowing or stopping. However, these bulkheads don't significantly reduce side-to-side surge, so rollovers can still occur.

Not quite. The answer is a high center of gravity.

It takes special skills to drive a tanker carrying liquid cargo because of the vehicle's high center of gravity and the possibility that the liquid cargo may surge forward and backward or from side to side. Much of a loaded tanker's weight is carried five or six feet above the ground. This makes a tanker top-heavy, which makes it more prone to rollovers than other types of vehicles. Tests have shown that a tank vehicle can roll over at the speed limits posted for curves. The safest way to take a curve in a tanker is to slow down well below the posted speed limit before you enter the curve.

Not quite. The answer is Slow down gradually.

Braking on a slippery surface can lock the wheels and cause a skid. Brake gently and slow down very gradually.

Not quite. The answer is allowance for expansion of liquid.

When liquid heats up, it expands, and outage is the space in the tank that is allocated to handle the expansion. Different types of liquids expand by different amounts. Therefore, the amount of outage you will need depends on the type of liquid.

Not quite. The answer is Environment

The S.T.A.M.P.E.D. acronym is widely used to assist you in obtaining the correct hoses and fittings for your needs. S: the required size of the hose; T: the temperatures to which the hose will be subjected; A: the application (use) to which the hose will be put; M: the types of material (liquid, gas, etc.) that will have to flow through the hose; P: the maximum working pressure of the hose; E: the required fittings at the ends of the hose; D: the date at which the hose must be delivered to you.

Not quite. The answer is surging.

When a tank is not completely filled, the liquid has room to move around. It can slosh back and forth or side to side. This is called surging.

Not quite. The answer is both of the above are true.

Some liquids expand significantly when they warm up. To fill a tank with such a liquid, you must leave some room in the tank (called "outage") to take the expansion. Also, some liquids are so dense that a full load may exceed the legal weight limit. For these reasons, you may not be able to fill your tanks completely.

Not quite. The answer is leaks.

When you inspect your tank vehicle, the most important thing to check for is leaking tanks. It is illegal to knowingly carry liquids or gases in a leaking tank. Check around and underneath the vehicle for any signs of leaks. Also check all tanks, hoses, pipes, and connections for leaks.

Not quite. The answer is bulkheads.

Separators that divide a space into liquid-tight compartments are called bulkheads. The tank on a tanker vehicle may have bulkheads to divide the tank into separate compartments.

Not quite. The answer is some liquids expand more than others when they get warm.

Different liquids expand at different rates as the temperature increases. In science, the percentage increase of expansion for a given change in temperature is called the coefficient of thermal expansion. This value depends on the type of liquid. You need to find out how much outage you will need to allow for the type of liquid you'll be hauling.

Not quite. The answer is the top of the tank

In general, the Maximum Allowable Working Pressure (MAWP) of a pressurized tank is the maximum pressure that the weakest part of the tank can handle in normal operation. For a cargo tank on a motor vehicle, the federal definition of MAWP assumes that the weakest part is at the top of the tank.

Source: 49 CFR 178.320

Not quite. The answer is the type of liquid.

Different liquids expand at different rates as the temperature increases. In science, the percentage increase of expansion for a given change in temperature is called the coefficient of thermal expansion. This value depends on the type of liquid. You need to find out the likely percentage increase for the type of liquid you'll be hauling, and allow enough room (called outage) for the expansion to take place.

Not quite. The answer is Read the vehicle's manual to learn how to do it.

Tank vehicles come in many models and sizes, each with special items that you need to check during an inspection. Read the vehicle's manual to learn how to inspect it properly.

Not quite. The answer is MC-306 (DOT-406)

MC-306 (DOT-406) cargo tanks carry liquids under very low or no pressure (maximum allowable pressure of 3 psi for MC-306 and 4 psi for DOT-406). The cargo tank has an oval or elliptical cross section and is usually compartmented. These tanks are commonly used to carry gasoline, diesel fuel or fuel oil, and other flammable liquids.

Not quite. The answer is Spring brakes (or wheel chocks)

When parking a tank trailer, you should always apply the parking brake. On a modern trailer equipped with air brakes, applying the parking brake control will exhaust air from the brake chambers and cause the spring brakes to come on. However, an old trailer may lack spring brakes and instead use compressed air to set the parking brakes. In this case, you must chock the wheels to prevent the trailer from moving. A leak somewhere in the air braking system may cause the parking brakes to fail eventually.